Viscosity control system

ABSTRACT

A fluid system including circulation of fluid by gravity in a variable projectory to a second station. The fluid reaching the second station is dependent upon the viscosity of the fluid whereby the lower the viscosity the more fluid will reach the second station. An air inlet pipe extending from the top of a solvent container is positioned in the second fluid station and thus will supply solvent to the first fluid station when insufficient fluid is in the second station to close off the air inlet pipe. The solvent is siphoned to the first fluid station and upon the level of fluid at the first station falling below the end of an air inlet pipe the siphon line will be exposed to air and thus stop the flow of solvent.

United States Patent [72] Inventor Mervin R. McBee 6107 Walnut Hill Drive, Des Moines, Iowa 50312 21 Appl. No. 804,960 [22] Filed Mar. 6, 1969 [45] Patented Aug. 3, 1971 54] VISCOSl'lY CONTROL SYSTEM 7 Claims, 1 1 Drawing Fig.

52 us. Cl 137/92, 73/56, 137/142 [51] Int. CL ..G05d 11/00 [50] Field of Search 73/56; 137/88, 92,142

[5 6] References Cited UNITED STATES PATENTS 2,590,538 3/1952 Huck 137/92 Primary Examiner- Laverne D. Geiger Assistant Examiner-David J. Zobkiw AnomeyZarley, McKee & Thom te ABSTRACT: A fluid system including circulation of fluid by gravity in a variable projectory to a second station. The fluid reaching the second station is dependent upon the viscosity of the fluid whereby the lower the viscosity the more fluid will reach the second station. An air inlet pipe extending from the top of a solvent container is positioned in the second fluid station and thus will supply solvent to the first fluid station when insufficient fluid is in the second station to close off the air inlet pipe. The solvent is siphoned to the first fluid station and upon the level of fluid at the first station falling below the end of an air inlet pipe the siphon line will be exposed to air and thus stop the flow of solvent.

PAIENIEU nus 3am 3,596,672

Maw/v70? M52 VIN E M0555 VISCOSITY CONTROL SYSTEM In working with fluid such as inks for printing applications it is important to maintain a consistent fluid viscosity to get a consistent result such as the printed image. For example, heavy and thick ink will give an excessively dark color while too light inks will produce a too light color. Accordingly, consistent color of ink may be maintained by holding the ink viscosity at a constant level.

The system of this invention contemplates in the embodiment shown a recirculation system whereby ink is supplied to a press and also to the viscosity control unit with return lines from both the press and the viscosity control unit being in communication with a reservoir and pump unit. The viscosity control unit of this invention will automatically supply the necessary amount of solvent to maintain the ink at the desired consistency which may be set within the unit.

The viscosity control unit works on the principle of the ink flowing from one station to another and when the viscosity is high the projectory will be short and will not maintain the level in the second station sufficiently high enough to keep an air pressure pipe closed which is in communication with the top of a solvent storage container and as a result the solvent will flow therefrom by being siphoned to the ink supply which in turn will thin the ink and increase the projectory thereof until it fills the second ink station to close the airline to the solvent container. The second ink supply station may be moved to require more or less of a projectory to fill the second ink supply station. Thus, it is seen there are no moving parts in this viscosity control system as its operation depends upon .inherent properties of the fluid moving through the system and making and breaking a siphon which injects a solvent when needed into the ink supply. It is apparent that any type of fluid may be controlled as to its viscosity by use of this system and the system is not restricted to inks.

These and other features and advantages of this invention will become readily apparent to those skilled in the art upon reference to the following description when taken into consideration with the accompanying drawings, wherein;

FIG. 1 is a schematic of the viscosity control unit in combination with an ink reservoir and the fountain of a printing press;

FIG. 2 is a perspective view of the viscosity control unit;

FIG. 3 is a fragmentary top plan view of the viscosity control unit;

FIG. 4 is a cross-sectional view taken along line 4-4 in FIG.

FIG. 5 is a cross-sectional view similar to FIG. 4 but showing the solvent container pivoted 90 for bleeding air from the system to begin the siphoning;

FIG. 6 is a cross-sectional view taken along line 66 in FIG.

FIG. 7 is a cross-sectional view taken along line 77 in FIG.

FIGS. 8, 9 and 10 illustrate the projectory on ink relative to the second ink supply station, showing the preferred projectory in FIG. 8, the projectory falling short of the supply station in FIG. 9 and allowing air to enter the air pipe extending into the solvent container, and the projectory in FIG. 10 fully reaching the second ink supply station and maintaining the air pipe in a closed condition thereby preventing addition of additional solvent to the ink supply; and

FIG. 11 is an end view of the viscosity control unit showing the solvent container pivoted to a position whereby it may be filled through the air inlet pipe.

The viscosity control unit of this invention is referred to generally in FIG. 2 by the reference numeral 10 and is seen in FIG. I incorporated into a system including an ink reservoir 12 and a printing press fountain 14. A pump 16 driven by a motor I8 supplies ink through a line 20, to an ink supply station 22 through a line 24. A return line 26 from container 28 is connected to the reservoir 12. Additionally ink is supplied from the line 20 to the ink fountain 14 through a line 30 and the fountain has return line 32 connected to the reservoir 12. Control valves 34 and 36 are provided in the lines 30 and 24 respectively.

The first ink supply station 22 is elevated as seen in FIG. 6 and has a metering outlet orifice 38 at the bottom thereof directed towards a second liquid supply station viscosity measuring tray 40 in the container 28.

The ink supplied to the elevated station 22 through the inlet conduit 24 is filtered througha screen 42 in the station 22 and flows out of the station 22 in one of several projectories as illustrated in FIGS. 6, 8, 9 and 10 by the streams of ink 44. Ink in excess of that which can be handled by the outlet 38 may overflow the station 22 as seen by the overflowing ink 46 in FIG. 6. It is further seen that a battle or dampening chamber 48 is formed by walls 50 and 52 to insulate the outlet opening 38 from the inlet pipe 24. The ink in the supply station 22 overflows the walls 50 and 52 into the chamber 48 and out through the metering outlet 38.

The viscosity measuring tray 40 is slidably mounted on upstanding parallel supportelements 54 which are engaged by downwardly extending guide elements 56 on the tray 40. Viscosity measuring indicia 58 is provided on the support elements 54 to register with the end of the tray 40. The tray 40 is provided with an outlet opening 60 for ink to flow into the container 28 for return to the reservoir 12 through the outlet return line 26 as seen in FIG. 6. It is seen that ink may also overflow the tray 40 into the ink container 28.

A solvent container 62 is pivotally mounted on a support member 64 above the ink supply stations 22 and 40. The solvent container 62 is rectangular in cross section and is pivotally supported at one corner 64. As seen in FIG. 6, the container is substantially filled with liquid solvent 66 and air is admitted into the container only through an air pipe 68 extending from adjacent the top wall 70 in the container diagonally downwardly through the bottom wall 72 into the tray 40. Air as indicated by the arrows 74 may enter the lower end of the air pipe 68 whenthe ink 76 in the tray 40 is below the lower end of the air pipe thus leaving the air pipe open. Accordingly the air moves upwardly through the air pipe 68 to the top of the solvent container 62 and pushes downwardly on the solvent 66 to permit it to flow out an outlet pipe 78 connected to the solvent container closely adjacent the pivotal corner 64. It is noted that the outlet opening is closely adjacent the bottom wall 72 and thus will permit maximum utilization of the solvent 66 and is close to the sidewall 80 as seen in FIG. 5 to permit bleeding of the outlet line 78.

It is seen in FIG. 6 that the outlet line 78 extends upwardly from the bottom of the solvent container 62 and is in communication with the bottom of a chamber 82 in a glass jar 84. A line 86 extends from the bottom of the jar 84 in communication with the chamber 82 downwardly where it communicates with the ink supply station 22. Additionally, a pipe 88 extends through the bottom of the jar 84 to closely adjacent the top thereof above the solvent 90 in the jar and extends downwardly through the jar bottom where it terminates in a lower end portion positioned in the ink supply station 22. The lower end 92 of the pipe 88 is positioned in the ink supply station 22 at an appropriate height such that when ink is flowing through the station 22 it willclose off the end portion 92 so that air is not introduced into the solvent line 78 and specifically into the chamber 82. Conversely should the ink supply line 24 by closed then air will enter the solvent line 78 and stop the flow of solvent from the container 62 into the ink supply station 22. The enlarged end 92 will prevent the line 88 from being closed inadvertently by surface tension of the ink in the line.

In FIG. 5 the solvent supply outlet line 78 is being bled of air to start the siphoning of the solvent from the container 66 to the ink supply station 22. The solvent container 62 is pivoted 90 such that the solvent may flow by gravity out the line 78 and into the chamber 82 thence through the pipe 86. Once the solvent starts to flow from the end of the line'86 the container is pivoted back to its upright position as seen for example in FIG. 4 where it may then supply solvent to the ink supply station 22.

It is noted that as seen in FIG. 3 the solvent lines 78 and 86 and the air line 88 are all connected to the jar 84 in a common plane and all pivot with the container 62 when pivoted to the position shown in FIG. 5 for bleeding the solvent line. The air line 88 is ofi'set such that its outer end 92 is in a raised position when the system is being bled to avoid solvent flowing from the air line and thus the flow of solvent is restricted to the line 86 only.

The operation of the viscosity control unit is automatic and simple and involves no moving parts. It is seen that the solvent container 62 is filled with solvent 66 by pouring it through the air inlet pipe 68 when the container is pivoted 180 to the position of FIG. 11. The end of the pipe 68 in the container 62 being closely adjacent the top wall 70 permits the container to be pivoted back to the normal upstanding position of FIG. 7 without solvent entering the air inlet tube 68. Next the solvent line 78 is bled of air so that the siphoning of solvent may begin and thus this is accomplished by pivoting the container 62 to the position in FIG. 5 90 from the normal upright position. Then the container 62 is returned to its normal upright position with the air pipe 88 extending its lower end 92 into the ink supply 48 as seen in FIGS. 6 and 7 thus permitting solvent to flow when the air inlet pipe 68 is open as seen for example in FIG. 9. The ink supply is maintained through the inlet pipe 24 feeding the elevated ink supply station 22 which flows through the screen 42 and over the baffle structure into the chamber 48 where it thereupon flows out the outlet metering orifice 38 to form a projectory 44 as seen in'FIGS. 6, 8, 9 and 10. In FIG. 8 the projectory 44 of ink is split by the end wall 100 which serves as a dividing wall and accordingly a portion of the ink flows into second liquid supply station the tray 40 and a portion flows into the container 28 for return to the reservoir through the pipe 26. As long as the stream of ink in the projectory is being split as seen in FIG. 8 the ink should rise high enough in the tray to close off the air inlet pipe 6 and thus prevent any solvent from being added to the ink supply station 22. The outlet opening 60 in the tray 40 along with the opening 38 may be varied appropriately to give the desired projectory. Once these variables have been set, the ink supply'having a too high viscosity will fall short of the tray as seen in FIG. 9 thus permitting air to enter the air pipe 68 and permit flow of solvent 66 to occur thus diluting the ink in the ink supply station 22 which in turn will cause the viscosity to be lowered whereby the projectory will be greater and the stream will return to the preferred projectory of FIG. 8. It is seen that the system is automatic in maintaining a consistent viscosity. Should the ink have a too low a viscosity the stream will form a projectory as seen in FIG. 10 and all of it will flow into the tray and perhaps overflow the tray but in any event no solvent will be added since the air inlet pipe 68 will be maintained in a closed condition.

It is seen that a visual inspection of the system can readily be made since essential structure is visibly accessible such as the solvent line 78 which flows through the chamber 82 in the jar 84. Furthermore, the viscosity may be readily changed by merely moving the tray 40 towards or away from the stream of ink 44. Viscosity readings are conveniently available on the scale 58 as seen in FIG. 6.

Some changes may be made in the construction and arrangement of my Viscosity Control System without departing from the real spirit and purpose of my invention, and it is my intention to cover by my claims, any modified forms of structure or use of mechanical equivalents which may be reasonably included within their scope.

lclaim:

1. A viscosity control system comprising,

a first liquid supply station adapted to feed a second liquid supply station,

a solvent supply station for feeding said first liquid supply station, the flow of solvent from said solvent supply station being responsive to the viscosity of liquid in said second liquid supply station whereby upon said liquid in said second liquid supply station reaching a first predetermined value said solvent supply station is triggered to feed solvent to said first liquid supply station and as a consequence of the viscosity value changing to a second predetermined value said feeding from said solvent supply station is stopped,

an outlet metering means on said first liquid supply station being positioned above and away from said second liquid supply station such that the transmission of liquid from said first liquid supply station to said second liquid supply station is by free fall gravity,

said second liquid supply station having a metering outlet,

said outlet metering means adapted to provide a liquid projectory varying with the viscosity of the liquid in said liquid projectory such that when said viscosity is at said first predetermined value at least a portion of said projectory of liquid is short of said second liquid supply station and when said viscosity is a said second value at least a portion of said projectory is into said second liquid supply station,

said solvent supply station including an enclosed container with an outlet means for siphon feeding said first liquid supply station, and an air inlet conduit having a lower open end positioned in said second liquid supply station, and in communication with the top of said enclosed container,

air pressure means including said lower open end of said air inlet conduit being closed by said liquid in said second liquid supply station when the level of liquid in said second liquid supply station is above the lower open end of said inlet conduit with said liquid viscosity at said second value and being open when the level of liquid in said second liquid station drops below the lower open end of said air inlet conduit with said viscosity at said first value.

2. The structure of claim 1 wherein said solvent container is rectangular in .cross section and said outlet means is a gravity feed outlet opening adapted to be in communication with said first liquid supply station, said solvent container being pivotally mounted to move through-an angle of rotation of between a feeding position and a bleeding position, said gravity feed outlet opening being positioned at the corner which is lowermost during the pivoting between said feeding and bleeding positions whereby said outlet opening is maintained in communication with solvent in said solvent container.

3. The structure of claim 1 wherein said solvent outlet means includes a solvent conduit in communication with an enlarged chamber between said solvent container and said first liquid supply station, an air conduit extends from within said first liquid supply container to said enlarged chamber, said air conduit adapted to have its open end closed by liquid in said first liquid station and opened upon the liquid in said first liquid station falling below the open end of said air conduit whereby air may be introduced into said enlarged chamber and said solvent conduit to stop the flow of solvent to said first liquid supply station.

4. The structure of claim 1 wherein said second liquid station is moveable relative to said outlet metering means whereby the viscosity of the liquid may be selectively varied.

5. The structure of claim 1 wherein said air inlet conduit extends through the bottom of said solvent container to the top therein, said solvent container being rectangular in cross section and pivotally supported to be turned to a filling position with said air inlet conduit extending upwardly to a position wherein the open end portion of said conduit outside said container is higher than the open end portion in said container whereby said container may be filled through said conduit.

6. The structure of claim 5 wherein said air inlet conduit is the only air opening into said solvent container to thereby control air pressure inside said container at the top thereof for controlling the flow of solvent from the container.

7. The structure of claim 1 wherein said second liquid supply station includes a container for liquid and said metering outlet on said second liquid supply station is in communication with said container said projectory of liquid from said tion having an upstanding divider wall and an open top, said liquid when at the selected viscosity having a projectory directing it at said divider wall with a portion going into said second supply station and a portion going outside thereof and first liquid supply station to said second liquid supply station 5 into said containerbeing adapted to be divided by the second liquid supply sta- 

2. The structure of claim 1 wherein said solvent container is rectangular in cross section and said outlet means is a gravity feed outlet opening adapted to be in communication with said first liquid supply station, said solvent container being pivotally mounted to move Through an angle of rotation of 90* between a feeding position and a bleeding position, said gravity feed outlet opening being positioned at the corner which is lowermost during the pivoting between said feeding and bleeding positions whereby said outlet opening is maintained in communication with solvent in said solvent container.
 3. The structure of claim 1 wherein said solvent outlet means includes a solvent conduit in communication with an enlarged chamber between said solvent container and said first liquid supply station, an air conduit extends from within said first liquid supply container to said enlarged chamber, said air conduit adapted to have its open end closed by liquid in said first liquid station and opened upon the liquid in said first liquid station falling below the open end of said air conduit whereby air may be introduced into said enlarged chamber and said solvent conduit to stop the flow of solvent to said first liquid supply station.
 4. The structure of claim 1 wherein said second liquid station is moveable relative to said outlet metering means whereby the viscosity of the liquid may be selectively varied.
 5. The structure of claim 1 wherein said air inlet conduit extends through the bottom of said solvent container to the top therein, said solvent container being rectangular in cross section and pivotally supported to be turned to a filling position with said air inlet conduit extending upwardly to a position wherein the open end portion of said conduit outside said container is higher than the open end portion in said container whereby said container may be filled through said conduit.
 6. The structure of claim 5 wherein said air inlet conduit is the only air opening into said solvent container to thereby control air pressure inside said container at the top thereof for controlling the flow of solvent from the container.
 7. The structure of claim 1 wherein said second liquid supply station includes a container for liquid and said metering outlet on said second liquid supply station is in communication with said container said projectory of liquid from said first liquid supply station to said second liquid supply station being adapted to be divided by the second liquid supply station having an upstanding divider wall and an open top, said liquid when at the selected viscosity having a projectory directing it at said divider wall with a portion going into said second supply station and a portion going outside thereof and into said container. 